Furnace



Mare 27 1923., EASQJZ? H. E. WITZ FURNACE Filed Nov. 9, 1922 I'NVENTQ'R.

Patented Mar. ,27, 1923.

K than? raraur errata.

HENRI EMIL WITZ, F REEINLAND BAIDEN, GERMANY, ASSIGNOR TO THE BABCOCK & 'W'JILCOK COMPANY, OF BAYONNE, NEW JERSEY, CORPORATION OF NEW JERSEY.

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Application filed November 9, 1922. Serial Eb. 599,763.

To all whom it may concern."

Be it known that 'l, HENRI EMIL Wrrz,

a citizen of the Republic of Germany, residing at Stockmannstrasse 158, Uberhausen, Rheinland Baden, Germany, have invented certain new and useful Improvements in Furnaces, of which the following is a specification.

My present invention relates to furnaces in which fuel with a considerable moisture content may be economically burned, and will be best understood from the following description and annexed drawings, in which Fig. 1 is a vertical section of one embodiment of my invention in connection with a chain grate Stoker; Fig. 2 is an arrange ment, partly in vertical section, of a form of my invention applied to a stepped grate, and Fig. 3 is similar to Fig. 2 showing a modification.

Like reference characters indicate like parts in the several views.

In the arran ement shown in Fig. 1, 10 is a combustion c amber beneath a boiler having tubes 11. A chain grate 12 of the usual construction is arranged to carry the fuel from a hopper 13 toward the combustion chamber 10 in the usual manner. A combustion arch 14 is provided above the forward end of the minated at its front by a movable provided with a screw and nut 16, whereby the distance between the gate 15 and the upper run of the grate 12 may be adjusted. The usual feed late the supply of fuel from the hopper 13 to the grate.

The space between the gates 15 and 17 constitutes a drying chamber 18, provided 0 with an outlet duct 19 connected to a fan, thefurnace stack, or the like, so as to create a suction therein.

Beneath the drying chamber. 18 and at the lower side of the upper run of the grate 12 is a draft box 20 communicating through separate ducts with an inlet pipe 21 which, in turn, is connected with a part of the combustion chamber 10, preferably the upper portion thereof adjacent the boiler tubes where thecombustion of the gases from the fuel on the grate 12 has been substantially completed. A damper 22 is arranged at the front of the draft box 20 so that fresh air may be supplied to the draft box to be mixed grate, the arch being tergate 15,,

flue 36, through which a portion of the hot gate 17 is provided to regu with the gases from the combustion chamber 10 in a regulated amount.

When the illustrative form of my invention shown in Fig. 1 is in use, fuel from the hopper rate within the dryin chamber. Hot gases om the combustion c amber 10 are drawn through the duct 21 and the draft box 20 and the. upper run of the grate into and through the fuel resting thereon and out through the drying chamber 18 and the outlet pipe 19 These heated gases remove the moisture content of the fuel, which, during the drying process, is held back by the gate 15 on the dryin area of the grate until the fuel is sutlicient y dry to be ignited on. the combustion area of the grate 12. By allowing fresh air to pass the damper 22, the proper amount of gases to be drawn from the chamber 10 may be regulated to give the best results.

The arrangement shown in F ig. 2 is similar to that shown in Fig. 1 except that the grate 30 is of the ordinary stepped form, having a dry area 31 to which fuel is supplied by the feed gate 32, this fuel belng held back thereon by a gate 33, the height of both of these gates being regulated in the usual manner. Beneath the portion of the grate 31 is a draft chamber 34 connected tdt,

an inlet duct 35 connected with a waste gas gases from the boiler may be drawn. A branch duct 37 provided with a damper 38 permits fresh air to be admitted to the duct 35.

Above the grate 31 is a drying chamber 39 connected with an outlet duct 40 which, in turn, is connected to a centrifugal separator 46, the outlet of which is connected through a pipe 47 with the inlet side of the fan 41, the exhaust side of which connects through a pipe 42 with the waste gas flue of the boiler.. The inlet side of the fan is also provided with a branch duct 43 having a damper 44 and the pipe 40 is provided with a damper 45.

As described in connection with Fig. 1,

the fuel on the drying portion 31 of the grate is dried by hot gases drawn from the boiler outlet through the pipe 35 by the fan 41'. such gases passing from the box 3a through the fuel and the pipes 40 and 42 to the stack. The gate 35 holds the fuel 13 passes under the gate 17 to the.

back until it is properly dried. The dam- I 4 pers 45 and 44 may be utilized to regulate the amount of gases being drawn through the fuel and the damper 38 may be used to regulate the mixture of. fresh air with such gases to produce the best results.

The separator 46 in the form shown in Fig. 2 is provided for fuel containing a con siderable amount of fine dust which would 1 be drawn out of the fuel and passed directly into the stack, if the'sepa-rator were not provided. If desired, this separator may be omitted, and the gases passed directly from the pipe 40 into the inlet side of the fan 41. l 1 a In Fig. 3 the arrangement is similar to that shown in Fig. 2, except that all of the gases from the combustion chamber of I the boiler or the like pass through the dust 50 and an air heater 51 into the box 52 and from thence through the drying grate 53 into the drying chamber 54' and the'pipe 55, suction being created by a fan 56. The gate 57 holds back the fuel delivered to the grate 53 from the hopper 58 until it is sufficiently dry, when it passes to the combustion area of -the grate 59.

In this embodiment of my invention, all of the gases "flow through the fuel being dried, butlsi'iice such gases are usually more than suflicient in volume and heat for such purpose, I abstract some of the heat thereof by means of the air heater 51, so that the air used for combustion on the grate 59 will be preheated while there stillwill besuflicient heat in the gases passing through the grate to dry the incoming fuel.

It will be understood thatthe embodiments of my invention are merely illustrative and that the forms thereof may be widely varied.

I claim:

1. In a furnace, a grate having a fueldrying area and a fuel-combustion area, a drying chamber above the fuel-drying area, a valve to regulate the flow of fuel from the drying area to the combustion area, and means to pass heated furnace gases upward through the fuel on said drying area.

2. In a furnace, a grate having a fueldry-ing area and a fuel-combustion area, a drying chamber above the fuel-drying area, a valve to regulate the flow of fuel from the dryingarea to the combustion area, and means for passing heated gases from a. point of substantially complete combustion in the combustion chamber through the fuel on the fuel-drying area. 1

3. In a furnace, a grate having a fueldrying area and a fuel combustion area, a drying chamber above the fuel-drying area, a valve to regulate the flow of fuel from the drying area to the combustion area, means for passing heated furnace gases in regulated amounts through the fuel on said drying area, and means to mix air with the gases before they pass through such fuel.

HENRI EMIL WITZ. 

